ור' יהודה אכילה כתיבה ביה ורבנן ההיא אכילה דכי אית ביה ארבעה וחמשה זיתים ואכל חד כזית מיחייב
And what does Rabbi Yehuda hold? He holds that since the term: Eating, is written with regard to the sciatic nerve, and a significant act of eating is generally defined as eating an olive-bulk, one is liable only if he eats an olive-bulk. And what do the Rabbis derive from this term? That usage of the term eating indicates that in a case where the sciatic nerve contains four or five olive-bulks and one ate only one olive-bulk, he is liable. Nevertheless, if one eats the entire sciatic nerve, he is liable even if it contains less than an olive-bulk.
ורבי יהודה מאשר על כף הירך נפקא
And according to Rabbi Yehuda, from where is it derived that one is liable for eating one olive-bulk of a larger sciatic nerve? He holds that it is derived from the phrase “that is upon the spoon of the thigh,” which indicates that even if one eats only the part of the sciatic nerve that is upon the spoon of the thigh, rather than the entire sciatic nerve, he is liable.
ורבנן ההוא מיבעי ליה לכדשמואל דאמר שמואל לא אסרה תורה אלא שעל כף הירך ור' יהודה הירך כתיב דכולה ירך
And how do the Rabbis interpret that phrase? That phrase is necessary to teach the halakha stated by Shmuel, as Shmuel said: The Torah prohibits only the part of the sciatic nerve that is on the rounded protrusion of flesh shaped like a spoon. And what does Rabbi Yehuda hold with regard to the halakha stated by Shmuel? He derives from the fact that it is written: “The spoon of the thigh,” that the sciatic nerve of the entire thigh is forbidden, not just the part that is on the rounded protrusion of flesh shaped like a spoon.
ורבנן ההוא דפשיט איסוריה בכוליה ירך לאפוקי חיצון דלא ולעולם שעל הכף
And how do the Rabbis interpret “the spoon of the thigh”? According to the Rabbis, this expression indicates that the prohibition of the sciatic nerve applies to the nerve that extends throughout the entire thigh, i.e., the inner nerve, which serves to exclude the outer nerve, which is not forbidden by Torah law; but in fact, only the part of the inner nerve that is on the protrusion of flesh shaped like a spoon is forbidden, not the entire inner nerve.
והאי כף מיבעי ליה למעוטי עוף דלית ליה כף תרי כף כתיבי:
The Gemara objects: But this term “spoon” is required to exclude the sciatic nerve of a bird, which does not have a rounded protrusion on its thigh bone that can be described as the spoon of the thigh, as taught in the mishna (89b). The Gemara explains: There are two usages of the term “spoon” written in the verse, and therefore two separate halakhot can be derived from this term.
מתני׳ ירך שנתבשל בה גיד הנשה אם יש בה בנותן טעם הרי זו אסורה כיצד משערין אותה כבשר בלפת
MISHNA: In the case of a thigh that was cooked with the sciatic nerve in it, if there is enough of the sciatic nerve in it to impart its flavor to the thigh, the entire thigh is forbidden for consumption. How does one measure whether there is enough sciatic nerve to impart flavor to the meat of the entire thigh? One relates to it as though the sciatic nerve were meat imparting flavor to a turnip. If meat the volume of the sciatic nerve would impart flavor to a turnip the volume of the thigh when they were cooked together, then the entire thigh is forbidden.
גיד הנשה שנתבשל עם הגידים בזמן שמכירו בנותן טעם ואם לאו כולן אסורין והרוטב בנותן טעם
With regard to a sciatic nerve that was cooked with other sinews, when one identifies the sciatic nerve and removes it, the other sinews are forbidden if the sciatic nerve was large enough to impart flavor. And if he does not identify it, all the sinews are forbidden because each one could be the sciatic nerve; but the broth is forbidden only if the sciatic nerve imparts flavor to the broth.
וכן חתיכה של נבלה וכן חתיכה של דג טמא שנתבשלה עם החתיכות בזמן שמכירן בנותן טעם ואם לאו כולן אסורות והרוטב בנותן טעם:
And similarly, in the case of a piece of an animal carcass or a piece of non-kosher fish that was cooked with similar pieces of kosher meat or fish, when one identifies the forbidden piece and removes it, the rest of the meat or fish is forbidden only if the forbidden piece was large enough to impart flavor to the entire mixture. And if he does not identify and remove the forbidden piece, all the pieces are forbidden, due to the possibility that each piece one selects might be the forbidden piece; but the broth is forbidden only if the forbidden piece imparts flavor to the broth.
גמ׳ אמר שמואל לא שנו אלא שנתבשל בה אבל נצלה בה קולף ואוכל עד שמגיע לגיד
GEMARA: The mishna teaches that a thigh that was cooked with the sciatic nerve is forbidden if the nerve imparts flavor to the thigh. Shmuel says: The Sages taught that the thigh is entirely forbidden only when it was cooked with the sciatic nerve inside it. But if the sciatic nerve was roasted inside the thigh, one may peel away the meat and eat it until he reaches the sciatic nerve, and then he removes the nerve.
איני והאמר רב הונא גדי שצלאו בחלבו אסור לאכול אפילו מראש אזנו
The Gemara challenges: Is that so? But doesn’t Rav Huna say: With regard to a kid that was roasted with its forbidden fat, it is prohibited to eat any part of the animal, even from the top of its ear? This proves that roasting, like cooking, spreads the flavor of the forbidden fat throughout the entire animal.